(WAYNESVILLE) - The Bartholomew County sheriff said on Tuesday his investigators are considering a quadruple homicide drug-related.

WISH TV8 reports, Sheriff Mark Gorbett spoke briefly to the media at noon on Tuesday and addressed widespread speculation that the murders were tied to drugs.

Gorbett said the son, who discovered the bodies Saturday night, is not considered a suspect. His call to 911 was released on Tuesday. The sheriff's department has interviewed two persons of interest, but no arrests have been made as of Tuesday afternoon.

Bartholomew County Coroner Larry Fisher says the four victims that were killed inside a Waynesville home Saturday died from multiple gunshot wounds.

During the afternoon news conference, Fisher described the murders as "violent" and "brutal."

Police said Thomas Smith, 39, and his girlfriend, 53 year-old Katheryn Burton, were shot to death inside the Waynesville home . Investigators also found the bodies of 41-year-old Aaron Cross and 41-year-old Shawn Burton.

Fisher says initially, he thought they died from single gunshot wounds, but after performing autopsies, he said the victims died of multiple gunshot wounds. Katheryn Burton also suffered multiple stab wounds.

Forensic analysis is still ongoing. Authorities recovered a rifle from near the scene but need that analysis to know if it was the weapon used in the murders. Investigators also found methamphetamine, spent shell casings and a knife used in one of the homicides at the scene.